Minimum Font Size Checker http://coding-and-design.blogspot.de/2016/10/minimum-font-size-checker.html

MinimumFontSizeChecker.js

var 凸 = (function(凸) {
	"use strict";
	var W = window,
		D = document,
		minFontSize,
		floatMinFontSize,
		newColor,
		walkDOM = function (node, func) {
			if (node.nodeType === 1) {
				func(node);
			}
			node = node.firstChild;
			while(node) {
				walkDOM(node,func);
				node = node.nextSibling;
			}
		},
		markElement = function(node) {
			var min = minFontSize || "14px";
			var fontSize;
			if (! node.getAttribute("sfc-originalStyle")) {
				fontSize = W.getComputedStyle(node, null).getPropertyValue("font-size");
				if (parseFloat(fontSize) < floatMinFontSize) {
					node.setAttribute("sfc-originalStyle", node.getAttribute("style"));
				}
			}
		},
		resetElement = function(node) {
			if (node.getAttribute("sfc-originalStyle")) {
				if (node.getAttribute("sfc-originalStyle") === "null") {
					node.removeAttribute("style");
				} else {
					node.setAttribute("style", node.getAttribute("sfc-originalStyle"));
				}
				node.removeAttribute("sfc-originalStyle");
			}
		},
		activateElement = function(node) {
			if (node.getAttribute("sfc-originalStyle")) {
				node.style.fontSize = minFontSize;
				node.style.color = newColor;
			}
		};
	凸.SmallFontChecker = {
		highlight: function(size, color) {
			minFontSize = size || "14px";
			floatMinFontSize = parseFloat(minFontSize);
			newColor = color || "rgba(200, 0, 255, 1)";
			walkDOM(D.body, markElement);
			walkDOM(D.body, activateElement);
		},
		reset: function() {
			walkDOM(D.body, resetElement); 
		},
	};
	return 凸;
}(凸 || {}));

Documentation here: http://coding-and-design.blogspot.de/2016/10/minimum-font-size-checker.html